Charles l



(No Model.) 2 Sheets-Sheet 1L 0. L. BUGKINGHAM. SYNGHRONOUS MULTIPLETELEGRAPH.

No. 487,984. Patented Dec. 13, 1892. l

(No Model.) 2 Sheets-Sheet 2.

0. L. BUOKINGHAM. SYNUHRONOUS MULTIPLE TELEGRAPH.

487,984 Patented Dec. 13,1892,

Iine

UNITED STATES PATENT OFFICE.

CHARLES. L. BUOKINGHAM, OF NEWV YORK, N. Y.

SYNCHRONOUS MULTIPLE TELEGRAPH.

SPECIFICATION forming part of Letters Patent No. 487,984, dated December13, 1892.

v Application filed April 30, 1890. Serial No. 350,006. (No model.)

To all whom it may concern.-

Be it known that I, CHARLES L. BUOKING- HAM, a citizen of the UnitedStates of America, residing in the city, county, and State of New York,have made a new and useful Improvement in Synchronous MultipleTelegraphs, of which the following is a specification.

Heretofore synchronism has been established between rotating arms at thetwo ends of a line either by employing some of many transmissions forunison and the remainder for the sending of messages, as in the Delanysystem, or by using a continuous series of pulses to preserve unison andother values of current, either greater or less, for telegraphing.Patten employs a continuous series of weak pulses of alternatingpolarity for synchronism, while telegraph-signals are simultaneouslytransmitted by increasing the curent strength. By my improvement thearms at the two stations are synchronized by periodically transmittingfrom the receiving end of the line a pulse to the transmitting end,which there operates upon a relay controlling an adjusting mechanism,and it is by this means that a correcting-motor, which is geared withone of the trailing arms, is made once during each rotation of the otherarm to exercise either an accelerating or a retarding influence. Thecorrecting-motor is so constructed that when its armature occupies acertain position, it then requiring no adj ustment, the closing of thelocal circuit by the synchronizing-relay produces no effect upon themotor. If, however, the armature is moving too fast, there will be apath through the motor, by which the latter becomes an active agent toretard the speed of rotation, and in the same manner if the armature bemoving too slow there will be another path through the motor, such as tocause it to rotate more rapidly. As will be hereinafter seen, thesynchronizing-relay cannot be placed at the receiving-station, either inthe main line or in one of the branches. If the relay were placed in themain line, it would constantly respond to telegraph-pulses, thus closingthe local circuit of the synchronizing-motor out of time and derangingits action. Likewise if the relay were placed in a branch from one ofthe contacts of the circular series of segments and a correspondingbranch at the transmitter were provided with battery, the arrangementwould be inoperative, for in this case the relay would not close itscontact when the arms were running out of unison. It would only operatewhen the arms at the two stations Figure 1 is a diagram showing amultiple synchronous-telegraph system with an independently-actuatedmotor at each station for rotating the trailing arms. Fig. 2 representsa correcting-motor appended to a driving-motor to cause thelatter torotate more slowly or rapidly and to thus keep time with the trailer atthe receiving-station. Fig. 3 is a diagram of apparatus employed at thetwo stations to show the relative rates of the rotating arms.

In Fig. 1 I have shown six segments in the circular series of contactsover which the trailing-arms rotate, and to five of these segments areconnected conductors in which are placed keys K to K, and relays makingin such case a set of operators instruments. At the transmittingstationsegment 6 is connected to earth G while at the receiving-station segment6 is connected to the battery branch extending to earth G. At thetransmitting-station the trailer is geared with the shaft of anelectro-magnetic motor M, the. latter being continuously actuated by alocal battery, while an independently-actuated motor M is also employedat the receiving-station, it having as nearly as possible a speed ofrotation equal to that of M. To keep the two motors in unison, however,I place upon the shaft of M the armature c of a correcting-motor, whosefield-poles, as here shown, are extensions from the field-magnets of M.This auxiliary motor is so designed that when in a certain position-aposition of adj ustmentif the local circuit 50 be closed, no currentwill find a path through its armature. In most positions, however,whether at one side or she other of this point there will be a currentformed through some of its coils.

Referringto Fig. 2, I have shown a modified Gramme armature motorconsisting of two field-poles, an annular iron armature, and acontinuous winding broken at one point. This armature is provided withan ordinary sectional commutatorp, the segments, all but one, beingconnected to the armature-coils by wires numbered from 1 to 29. Thesegment q, connected with wire 15, however, is prolonged and is inmetallic connection with a ring 0, against which bears the spring 8, thelatter also being in electrical connection with the pivotal bearing ofthe armature-lever of relay D M. Spring 01 bears upon commutatorp and isconnected to one pole of the battery b and to the front contact of relayD M. It is now seen that if the relay-armature were attracted when themotor-armature is in the position shown in Fig.2 the current frombattery b would not find a path through any of the coils of themotor-armature, the circuit from brush n to s in this case being formedthrough segment q and ring 0. If, however, the motor armature wererotated to the left there would be a circuit through the coils to theright of wire 15 and through as many of them as are represented by thedisplacement which the armature has undergone. A circuit would likewisebe formed through coils at the left of wire 15 if the armature werethrown to the right. It now being remembered that the shaft of themotor-armature is rigidly fixed to the trailing arm at thetransmitting-station, it is seen that if the arms at the-two stationsare rotating in synchronism segment q will be in contact with brush 01while said arms are in contact with segments 6. It is obvious thatcurrent will not under this condition flow through any of the coils ofthe auxiliary motor-armature. If, however, the trailer at thecorrecting-station were rotating too rapidly from right to left currentwould flow through some of the motor-coils at the right of wire 15. Ifthe trailer were rotating too slowly, current would flow through some ofthe coils to the left of wire 15, and there would be a circuit throughmore or less coils, according as the trailer was far or only a littleway out of adjustment. If the trailer were out of adjustment onequarterof a rotation, of course current would flow through coils coveringone-quarter of the armature annulus, and, indeed, a circuit might beformed through the entire number of coils either at the right or theleft of wire 15. With this arrangement it is obvious that when thetrailer and correcting-armatu re are far out of adjustment a largenumber of coils are .brought into circuit, thus producing a very strongcorrecting etfcct, and that the number of coils brought into actiondiminishes with the necessity for adjustment. Owing to this fact thearmature of the correcting-motor is gradually worked into a position ofadj u'stment, the adjusting effects being of a diminishing amount, and,as a consequence, a corrective force tending to throw the armature overthe line of adjustment from too fast to too slow or from too slow to toofast is avoided.

As has already been stated, a battery branch from segment 6 is joined toearth at the receiving-station, while at the transmitting-station is acorresponding branch which is unprovided with battery. Relay D M and thecorrecting-motor, as already stated, are placed at thetransmittingstation rather than at the receiving-station, because ifthey were placed at the latter the telegraphic pulses would derangeadjustment; but in order that the relay may not be actuated by pulses atthe transmitting-station it must be given a dupleX character. ing itofthe differential form, connecting one of its coils with an artificialline having a resistance Rh and a condenser O, as is ordinarily done induplex telegraphy. Any of the many well-known forms of duplex relay maybe used.

The system thus far described contemplates the transmission of messagesin one direction only and a series of transmitting-instruments K to K atone station and a corresponding series of receiving-instruments at theother end of the line; but messages may also be sent in the oppositedirection if the currents employed be of such a character as not tooperate the synchronizing relay, thereby causing the correcting-motor tooperate out of time. This difficulty is obviated by polarizing thesynchronizing relay D M, and by employing a battery in the branchleading from segment 6 of a polarity opposite to that of the batteriesused for telegraphing from the same station. It, for example, relay D Mis so polarized that it will respond to positive and not to negativecurrents, only negative currents can be used to telegraph toward thestation at which the relay is placed. In this manner messages may besent from both stations simultaneously, or all from the right to theleft station. As shown at the right sta- This I have done by maktion,the branch leading from segment 6 presents positive polarity to line towork the synchronizing relay. The transmitting-batteries brought intoaction by keys K to K therefore, must be of negative polarity in orderthat they may have no influence upon the synchronizing relay.

In Fig. 2 I have shown a hand-switch by which more or less resistancecan be brought into circuit 50 to regulate the effect of battery 1) uponthe correcting-motor.

In Fig. 3 I have shown means by which it may be determined visuallywhether the trailing arms at the two stations are rotating at the samespeed. In the local circuit 50 I place an electro-magnet whosearmature-lever carries a driving-pawl at one end which acts upon theteeth of a ratchet-wheel to rotate an indicator-arm "5 over a dial. Asimilar arrangement is operated by the branch circuit leading fromsegment 6 to earth G but in this case the branch must be provided with abattery. It is obvious that the ratchet controlled bycircuit is movedstep by step with each rotation of the trailer at the distant station,and thus it is seen that as arm 1' passes over the figures of dial D weareable to determine at what speed the trailing-arm at the distantstation is being moved. The indicator controlled by the branch leadingfrom segment 6 at the home station also indicates the speed at which thetrailing-arm at the home station is rotating, and by comparing themovement of the two indicators we may determine approximately whetherthe two trailing-arms are running at the same speed. If one is runningmore rapidly than the other, adjustment may be principally effected byadjusting the hand-switch shown in Fig. 2, and their rates havingbeenbrought to almost equal each other they may then be left to theautomatic correcting devices to further equalize their speeds and tokeep them in synchronism.

I do not limit myself to the use of the particular kind of motorhereinbefore described as included in the correcting-circuit foreffecting the synchronism, inasmuch as any other means suitable for thepurpose might be employed in the local correcting-circuit controlled bythe relay for effecting synchronism, my invention, so far as this partthereof is concerned, consisting, broadly, in the combination, with thesynchronously operating transmitter and receiver, of a duplex relay atthe transmitting-station, an actuating-motor for the transmitter, alocal correcting-circuit at such station, a duplex relay for controllingsaid local circuit, and a synchronizing-battery branch at thereceiving-station intermittently closed by the operation of a motorthereat.

What I claim, and desire to secure by Letters Patent, is

1. In a synchronous multiple telegraph, a synchronizing arrangementconsisting of a battery at the receiving-station, a duplex relay at thetransmitting-station, a local circuit, and a unison-motor controlledthereby, substantially as described.

2. In a synchronous telegraph, a synchronizing arrangement consisting ofa battery in a branch at one station, a duplex relay at the otherstation, a local circuit, and a unisonmotor controlled thereby,substantially as described.

3. In a synchronous telegraph, an independently-actuated motor at eachstation, a correcting-motor and a duplex relay for controlling the speedof one of said motors, and a synchronizing-battery at a distant station,substantially as described.

4. In asynchronous telegraph, an independently-actuated motor fordriving a rotating arm at each station, a synchronizing-relay and acorrecting-motor at one station, the armature of the correcting-motorbeing so constructed that a circuit will be found through certain coilswhen it is rotating either too fast or too slow, but not otherwise.

5. In a synchronous-telegraph system, an independently-actuated motor M,geared with a trailing arm, a correcting-motor having an armature 0,provided with a broken Gramme winding, a sectional commutator 10, a ring0, electrically connected with segment q, brushes 5 n, relay D M, and abattery at the distant station for operating the same, substantially asdescribed.

6. In a synchronous telegraph, the combination of a trailing arm at onestation, adapted to rotate over a circular series of electricalcontacts, an actuating-motor M, geared with said arms, acorrecting-motor whose armature c is provided with a broken winding andis mounted upon the same shaft, a sectional commutator, and a ring withwhich one of the segments of the sectional commutator is electricallyconnected, and contact-brushes s n, substantially as described.

7. In an electro-magnetic motor, the combination of a ring-armaturewhich is providedwith a broken winding, a sectional commutator p, a ring0, a prolonged segment q, and brushes n s.

8. In an electro-magnetic motor, the combination of an armature providedwith a broken series of actuating-coils, a sectional commutator 19, ring0, brushes n s, and a local circuit for actuating said motor, wherebythe actuating-current will find a path through certain coils and in suchmanner as to give it a tendency to rotation either in one direction orthe other, substantially as described.

9. In a synchronous-telegraph system, two indicators at one stationcontrolled, respectively, by the rotating arms of the synchronoustelegraph, one at each end of the line, whereby it may be determinedwhether the telegraph apparatus at opposite ends of the line arerotating at equal speeds, or approximately so.

10. In a synchronous multiple telegraph, two independent step-by-stepindicators operated, respectively, by pulses transmitted over thetelegraphic circuit from the distant station and by pulses which arecalled into action by a device moving synchronously with the telegraphapparatusat the same station. r

11. In a synchronous multiple telegraph, a sunflower or its equivalentat eachstation, a synchronizing device insensible to telegraphic currenttransmitted from the same station as well as to telegraphic currentsfrom the opposite station, and means for transmittingsynchronizing-pulses from such opposite sta- IIO tion independently ofthe telegraphic currents.

12. The combination, with the synchronously-operated transmitter andreceiver, of a duplex relay at the transmitting-station, anactuating-motor for the transmitter, a local correcting-circuit at suchstation, a duplex relay for controlling said local circuit, and a forcorrecting devices at the same station synchronizing-battery branch atthe receiving-station intermittently closed by the operation of a motorthereat.

13. In a synchronous telegraph, a synchronizing arrangement comprising agenerator 1n a branch at one station and a duplex relay at the otherstation controlling alocal circuit with said relay, as and for thepurpose de- 10 scribed.

Witnesses:

C. W. CONKLIN, JOHN C. SANDERS.

